Add progressive web app companion for cross-platform access

Vite + TypeScript PWA that mirrors the Android app's core features:
- Pre-processed shelter data (build-time UTM33N→WGS84 conversion)
- Leaflet map with shelter markers, user location, and offline tiles
- Canvas compass arrow (ported from DirectionArrowView.kt)
- IndexedDB shelter cache with 7-day staleness check
- Service worker with CacheFirst tiles and precached app shell
- i18n for en, nb, nn (ported from Android strings.xml)
- iOS/Android compass handling with low-pass filter
- Respects user map interaction (no auto-snap on pan/zoom)
- Build revision cache-breaker for reliable SW updates

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

pwa/node_modules/fast-json-stable-stringify/benchmark/index.js

@@ -0,0 +1,31 @@
+'use strict';
+
+const Benchmark = require('benchmark');
+const suite = new Benchmark.Suite;
+const testData = require('./test.json');
+
+
+const stringifyPackages = {
+  // 'JSON.stringify': JSON.stringify,
+  'fast-json-stable-stringify': require('../index'),
+  'json-stable-stringify': true,
+  'fast-stable-stringify': true,
+  'faster-stable-stringify': true
+};
+
+
+for (const name in stringifyPackages) {
+  let func = stringifyPackages[name];
+  if (func === true) func = require(name);
+
+  suite.add(name, function() {
+    func(testData);
+  });
+}
+
+suite
+  .on('cycle', (event) => console.log(String(event.target)))
+  .on('complete', function () {
+    console.log('The fastest is ' + this.filter('fastest').map('name'));
+  })
+  .run({async: true});